The finale of Mozart's Don Giovanni is terrifying. But the preceding scenes, for the most part, are highly enjoyable silliness. Act II opens with Giovanni boisterously chiding his hapless servant Leporello (a brilliantly rendered stock buffo character, recognizable for his rapid patter and continual complaining). There follows vintage farce in which Giovanni uses Leporello as bait for former girlfriend Elvira, gives the slip to hordes of vengeful peasants and still finds time to attempt some seducing.

A momentary chill note slips in when Giovanni and Leporello reconnoitre in a graveyard (Leporello has just escaped from furious nobles thinking he's Giovanni; Giovanni is fresh from an encounter with Leporello's girlfriend). Their bantering recitative receives an alarming interruption from the statue of the murdered Commendatore. The audience at the premiere would have received a double shock from the use of trombones in the Commendatore's accompaniment; at Mozart's time trombones were almost exclusively played in church, and thus had connotations of serious ritual and authority (see Mozart's later use in the 'Tuba mirum' of his Requiem). They still have an impact for a modern audience today, if only because Mozart has waited so late in the opera to use them.

But the trombones and the Commendatore disappear soon enough, and the following duet, where Leporello cringingly invites the statue to dinner on his master's orders, is back in the lively comic vernacular. A few scenes later the finale also opens in upbeat mood, with Giovanni guzzling his dinner to Leporello's envious groans. He's arranged some light entertainment from an onstage wind band, who play a few popular tunes. Mozart pops in a little in-joke for his Prague premiere audience by including his own 'Non più andrai'; the fantastic success of Le nozze di Figaro in Prague had directly led to Don Giovanni's commission.

The sense of playfulness continues even as an incoherent Elvira runs in to make a last-ditch attempt to save Giovanni, and even as Leporello tremulously describes the arrival of the stone Commendatore ('ta-ta-ta-ta!' he emphatically exclaims, describing the statue's dreadful tread). The orchestra mimics Leporello as under Giovanni's orders he shrinkingly approaches the door to let the ghost in. There's silence, then a short minor chord, then another silence.

Then the Commendatore enters to a massive diminished 7th, a dissonant, eerie chord built of consecutive minor 3rds. It's played fortissimo across the whole orchestra, with those dread-laden trombones and a drum roll from the timpani. The structure of the music, with a pulsing in the violins, immediately recalls the dramatic opening of the overture – but so much more so. It is a massive, furious gesture, as the drama veers into horror.

The Commendatore delivers his dire message of doom to music that quotes much from the first part of the overture – a steady long-short-long pulse; rising and falling scales in the violins and flutes; a mournful offbeat figure in the violins, underpinned by seething semiquavers – but here they are heightened through chromatically rising elongated phrases that build unbearably. By the time Don Giovanni defiantly grasps the Commendatore's hand and gasps at its coldness, Mozart only needs mark it with a piano tremolando, and our hearts freeze with Giovanni's.

Given the musical horrors around him, Giovanni's continued refusal to repent is agonizing: with Leporello we urge him 'say yes, say yes!'. It's too late, and after librettist Lorenzo Da Ponte's brazenly laconic stage directions, 'Fire on all sides; earthquake', Don Giovanni finally meets his end in a blistering major cadence. And then…

Out of a black sky – blue! The rest of the cast denounce the rotten behaviour of the happily vanished Giovanni, in a wonderfully chirpy final ensemble rich in imitation and melodic invention. It's a quicksilver change of mood, but with the same pulse as the preceding music and a consistent sense of dramatic richness. Mozart denies us a tragic end and instead gives us a whole lot more: he sends us out moved, joyous and wonderfully entertained.

As you will know, Mozart himself had different versions of this opera. In Prague he included the whole finale, in Vienna he ended the opera straight after Don Giovanni's death.

We attempt to keep the morale of the sixtet 'Questo e il fin di chi fa mal', and to avoid the abrupt ending straight on Giovanni's death, but still to avoid the digression with the future of the other characters. At this point, we wanted the focus to stay on Giovanni, his destiny, and what hell is like for him, rather than to go back to what happens next to the others.

As Mozart himself had different versions of the ending, there is no final version of the ending of the opera, but still of course the cut we suggest is not normally done.

As a latecomer to opera - and to this thread - I very much appreciate the insights I gain from these articles. Thank you.

On the playing of 'Non più andrai' at Don Giovanni's final feast, however, I feel there's a bit more to it than just the success of Le Nozza di Figaro in Prague. I feel Mozart was using Figaro's words to Cherubino to directly address the Don.

"No more flitting around night and day like an amorous butterfly disturbing the ladies you Narcissus, you Adonis of love!"

With emphasis on the "No more!", for one way or the other - repentance or damnation - Don Giovanni's amorous days are over. So when Leporello says "I know this piece only too well", he's probably sung it - under his breath - a few times.

It's been many years - indeed, many decades - but I still recognise the symptoms that Cherubino lists in "Non so più cosa son, cosa faccio" as being those of a raging hormone attack on the body of an adolescent boy, and the answer the ladies give to the question he poses in "Voi che sapete che cosa e amor" is clearly "No, it's not love you're suffering from, Cherub, but lust! Now leave us alone!", so perhaps Mozart was making a direct connection between Cherubino and Don Giovanni: "Unless you grow up and settle down kid, you'll end up dragged down to Hell!"